The shortest day of the year, known as the Winter Solstice, takes place in the Northern Hemisphere around December 21 or 22 and June 20 or 21 in the Southern Hemisphere. At this time, one pole of Earth is tilted so far away from the Sun that it is at the farthest distance from it, with the least daylight.
The reason for this occurrence is the tilt of the Earth by 23.5 degrees about its axis. It is nearly elliptically shaped in its orbit pattern. This phenomenon occurs when the Sun is almost directly under the bottom of the sky chart during Winter Solstice time, precisely over the Tropic of Capricorn, located 23.5 degrees below North latitude. Thus, daylight times per day are very short.
Although daylight hours vary with latitude, areas near the poles often have significantly reduced daylight hours. Arctic Circle areas may even experience 24 hours of total darkness, a phenomenon referred to as the Polar Night.
Culturally, the Winter Solstice has been observed by civilizations as marking a turning point in the year, signaling the gradual return of longer days and renewal. Some famous observances include Yule in Northern Europe and ancient ceremonies at places like Stonehenge.
Although the Winter Solstice is the shortest day of the year, it does not represent the coldest day of the year. This lag, or seasonal lag, occurs because it takes the Earth’s oceans and landmasses some time to dissipate absorbed heat.
The Winter Solstice is a time-honored, deeply cultural, and symbolic occasion, marking the transition from darkness toward the light.